Overview

• Smoke from more than 700 active wildfires burning across Saskatchewan, Manitoba and Ontario is held in place by a high-pressure system stretching from the Upper Midwest to the Northeast.
• The National Weather Service has issued air quality alerts in at least 11 states, including Michigan, New York, Pennsylvania and Massachusetts, as PM2.5 levels reach Code Orange or higher.
• Air Quality Index readings have climbed into the “unhealthy” and “unhealthy for sensitive groups” categories, with Detroit ranking among the worst globally and parts of Minnesota and Wisconsin in the red zone.
• Health officials are urging sensitive populations—children, older adults and people with respiratory or heart conditions—to limit outdoor exertion, wear high-efficiency masks and use MERV-13 or higher air filters indoors.
• Local fires such as California’s Gifford Fire are compounding the smoke burden, and forecasters say wind shifts and an approaching cold front could begin clearing haze by midweek.